1. Field of the Invention
This invention relates to electrically conductive wire assemblies and is directed more particularly to such a wire assembly having utility in the construction of prototype circuits.
2. Description of the Prior Art
In the construction of one-of-a-kind circuits of some permanence, it is common to use a "breadboard", or "wire-wrap" panel. Such a board or panel is provided with a multitude of integrated circuit sockets, or pads, with a pin, typically 0.3 to 0.6 inch long, protruding from each socket connection. The pins are made of a hard metal. A circuit is constructed by wrapping wire tightly around the pins. It is common to use copper or silver plated copper wire of 26 or 30 gauge, covered by an insulative material.
A disadvantage experienced in the use of such wire is its lack of capability to provide shielding which is necessary to minimize coupling effects and provide a low impedance ground path. The presence of coupling interferes with the operating frequency of the circuitry, rendering the circuit less effective.
An alternative wire form used in breadboard constructions comprises a twisted pair of insulated wires. The twisted pair form can be effective in reducing magnetic pickup because the signals induced in successive twists cancel each other, at least to an extent, providing a shielding. However, the shielding is decidedly less than the desired 100%, leaving the wire vulnerable to coupling.
A further alternative embodiment is shielded coaxial wire. Such wires are generally provided with shielding in the form of a round conductor surrounding the usual circuit conductor wire and insulation. The use of the round conductor enlarges the diameter of the wire to a point at which the wire does not readily fit between the wire-wrap pins. Thinner coaxial wires are prone to breakage.
Accordingly, there is a need for a wire assembly suitable for use in the construction of breadboard prototypes, which wire assembly is shielded and of suitable configuration for breadboard use.